1. Field
This application relates to methods and apparatuses for correcting a positron emission tomography (PET) image.
2. Description of Related Art
Medical imaging devices that are used to obtain images of internal parts of a body to diagnose patients provide data required to diagnose diseases. Medical imaging methods currently used in hospitals or being developed are mainly classified into an anatomical imaging method and a physiological imaging method. Techniques for capturing high-resolution anatomical images of the body include magnetic resonance imaging (MRI) and computed tomography (CT). These techniques represent accurate positions and shapes of organs of the body by capturing a tomography image of the body or by generating a three-dimensional (3D) image based on a plurality of tomography images. A representative example of a physiological imaging technique is positron emission tomography (PET) for capturing images of internal parts of the body to diagnose a metabolic disorder.
PET is an imaging technology in which a special radioactive tracer for emitting positrons is generated in the form of a metabolic component and is introduced into the body via an intravenous injection or an inhalation method, and two gamma rays at 511 keV emitted in opposite directions when positrons emitted from the tracer combine with electrons are detected by an external device, thereby detecting the position of the tracer and observing a distribution pattern of the tracers and a distribution variation according to time.
In general, in comparison to the total number of actually generated gamma rays, only a very small number of gamma rays reach the detector due to dispersion or attenuation. Thus, a relatively long detection time of several minutes is required to ensure a sufficient amount of detected gamma rays. However, since organs of a healthy person move in relatively short cycles due to breathing or heartbeat, if images of a target are captured for several minutes, motion of the target is reflected in the images, and thus image blur occurs. The above phenomenon in which an image is blurred due to relative motion between an imaging device and a subject is referred to as motion blur, and is a main factor reducing the resolution of a PET image. A deblurring operation for compensating for motion blur is required to correct an image having motion blur. In general, the deblurring operation causes amplification of noise to infinity at certain frequencies.